Michael Lipp - 2012-05-10

Maintaining backward compatibility in tools development is always an extra effort. It may be worth it if you're a professional developer (and get paid for it, because it is also a rather boring issue) or if you aim at a really large and rather inexperienced user base.

Did you try to create a new project from scratch? If that doesn't work immediately, maybe also try using a new workspace and create a new project, because eclipse saves some configuration information in the workspace. Does that work for you?